LAUSR

BackgroundHead and neck Synovial sarcoma (SS) accounts for 3–10% of all total body SS. It is rare to find it in the oral cavity, especially on the floor of the mouth.Case presentationWe present a 44-year-old Chinese male, who had been misdiagnosed as fibroadenoma, with a swelling on the right submandibular region for more than 3 months. The radiology examinations and the pathology results indicate the diagnosis of SS of the floor of the mouth.The patient only had a surgical operation, without radiotherapy and chemotherapy. At the first follow-up, the patient exhibited no clinical or radiographic complications, and the patient was asymptomatic on subsequent visits.ConclusionsMisdiagnosis results the delay of diagnosis and treatment of SS. Immunohistological analysis might be the most important tool to confirm the diagnosis of SS.